The goals of this project are to detect and accurately describe peri- menopausal mood disorders, explore their pathophysiology and response to pharmacological and environmental manipulation, and to document the relationship between reproductive endocrine change and disorders of mood as a way of further investigating the neurobiology of psychiatric illness. Findings to date include the following: 1) significant improvement of multiple symptoms of perimenopausal depression following estrogen replacement in 28 women with perimenopausal depression; 2) decreased libido, sexual arousal, and erectile function in 11 men participating in the Lupron trial prior to testosterone addback; 3) decreased vigor and exercise-associated pleasure in men during the hypogonadal state.